一种具有瞬态增强的无片外电容型LDO

A Capacitor-less LDO with Transient Enhancement

提出了一种稳定性高、瞬态特性良好、无片外电容的低压差线性稳压器(LDO)。采用推挽式微分器检测负载瞬态变化引起的输出电压变化,加大对功率管栅极寄生电容的充放电电流,增强系统的瞬态响应能力;在误差放大器后接入缓冲级,将功率管栅极极点推向高频,并采用密勒电容进行频率补偿,使系统在全负载范围内稳定。基于TSMC 65 nm CMOS工艺进行流片,核心电路面积为0.035 mm^(2)。测试结果表明,最低供电电压为1.1 V时,压降仅为100 mV,负载电流1μs内在1 mA和150 mA之间跳变时,LDO的最大输出过冲电压与下冲电压分别为200 mV和180 mV。

A capacitor-less low dropout regulator(LDO)with high stability and good transient characteristic is proposed.The system’s transient response capability was improved by using the push-pull differentiator to detect the changes of output voltage caused by the load’s transient changes,and by increasing the charge and discharge currents of parasitic gate capacitors of the power transistors.After the error amplifier was connected to the buffer stage,the pole at the gate of the power transistor was pushed to the high frequency,and the miller compensation method was adopted to make the system stable within the full load range.The circuit was fabricated in TSMC 65 nm CMOS process,and the core circuit area was 0.035 mm^(2).The tested results show that when the minimum supply voltage is 1.1 V,the voltage drop is only 100 mV.When the load current changes between 1 mA and 150 mA at 1μs,the maximum overshot voltage and undershot voltage is 200 mV and 180 mV respectively.